Pipe coating



` 1PM 29, 94 K H. FULTON E2,240,334

' 4PIPE COATING Qriginal Filed Dec. 9; 1937 v fn? 7a f f Z/ lPatented Apr. 29, 1941 j PIPE cosmo Kai-1H. Fulton, Pittsburgh, Pa.

Continuation of applicati This 290,365

December 9, 1937. 1939, Serial No.

8 Claims.

This invention relates to the protective coating o! metal cylinders, and more particularly to improved method and apparatus for applyinga protective hardenahle liquid coating apparatus whereby thicker' more ings may be applied than has been heretofore practicable, and with a minimum erasure or damaging of the coating after application.

'With they above and other objects and features which is hereinafter described and more particularly deilned by the accompanying claims.

In the following description ,reference will be made to the accompanying drawing. in which:

Fig. 1 is a plan View of pipe coating apparatus built in accordance with the preferred design which forms the subject oi' the present invention;

Fig. 2 is a vertical side section, taken along line 2-2 of Fig. 1; and f Fig. 3 is a view in vertical end section taken along line 34 ci' Fig. 1;

` Fig. 4 ls an enlarged end view illustrating the manner of applying a coating to the external surface of a pipe section.

Referring to the drawing, the numeral l designates a tank adapted for holding a bath of the air or heat hardenable liquid with which the pipe s to be coated. Such liquid, for example,

on Serial No.

178,861, application August 16,

consistency for insuring application of a coating o1' desired thickness on theplpe i'or protection 'I'he tank i0 has least one and one-half times the circumference oi' the largest pipe to be coated.

l2 have their upper edges extending preferably only a few inches above the normal top level I6 of the bath o! coating liquid.

For the purpose of supporting a length of pipe A in the bath during the coating operation, a

Ii oi' the liquid bath.

A length of pipe which is to have its outside surface coated with the bath liquid is placed in surface ot the pipe with the coating liquid.

Since the apparatus oi the present invention or working edge of each The preferred equipment for accomplishing the above specified object comprises a crank shaft 22 which is Joux-nailed in bearings 24 1ocated along the side wall l2 over which the pipe section is removed from the tank As shown in the drawing, the longitudinal axis of the shaft 22 is positioned in a linewbich is closels1 spaced from and parallel to the said side wall of the tank and which is also closely spaced from and parallels the normal upper level of the liquid in the coating bath. A crank 26 is shown as attached to an end of the shaft 22 which extends beyond the end wall of the tank, by means of which power may be applied to rotate the shaft.

The pipe rolling and elevating elements yof the mechanism comprise at least two spaced fingerlike cams 28 which are rotatable by the shaft 22 in spaced vertical planes. The free unsupported ends of the cams 2B extend substantially the full width of the tank, and in their normal inoperative position are held by gravity with all but their extreme ends immersed in the bath. The upper cam is so shaped that as the shaft 22 is rotated through a substantially 90 angle in the direction in which it is desired to roll the pipe, the upper edge 29 of the free end of the cam 2B will engage and push the pipe along the rails i3 toward the ,convexly curved cam shoulders 30. As the cam continues to rotate the pipe is raised from the rails i8 on to the cam shoulders and is thereby elevated over the upper edge of theadjacent tank wall and discharged over the side of the tank on to tracks 32 over which the coated pipe is rolled into a drying oven 34. Tracks 32 are aligned with cams 28 in order that the pipe coating applied in the tank may not be marked except in rings at the line of contact of the pipe with the cam shoulders 30 and tracks 32. These rings may be later coated over by an automatic applicator.

By suitably adjusting the viscosity of the coating liquid in the bath and by continually rolling the pipe section through and out of the bath into and through the drying oven,'the pipe can be given a thick and full flood coating of substantially uniform thickness. The rolling of the pipe pei mits a greater thickness of coating film to be held on the pipe without draining olf.

It will be understood that a tank I suitably proportioned for handling pipe sections twenty feet in length by twenty inches diameter would have side walls l2 much longer in proportion to the length of the end walls i4 than the tank which is illustrated in Fig. l. Likewise it will be understood that for handling pipes of' greater diameter the relative dimensions and shape of the cam 28 illustrated in Fig. 3 would have to be modified to some extent. The important feapreliminary to discharge from the tank on to the rails 32.

The invention having been is claimed as new is:

1. In pipe coating apparatus, an open top tank for coating liquid, work supporting rails mounted at spaced intervals transversely of said tank with thus described what y their upper edges in the same horizontal plane,

tures of the cam mounting and shape would however remain substantially as illustrated, with the shaft 22 journalled in the tank in a position closely adjacent and parallel to the surface of the coating bath and the side wall of the tank over Y which the coated pipe is discharged. The Working surface 29 of the free end of the cam preferably has a radius of curvature more than double the radius of curvature of the convex pipe elevating surface 3U, and the two surfaces 29 and .3D intersect to 'form an angle therebetween greater than 90 (preferably 120-l30). Since two or more cams 28 are mounted on the same shaft 2? at spaced distances along the lengths of `the tank, these cams in operation serve to align the pipe A with the sides I2 of the tank before the pipe is elevated on the edge 30 of the cams the upper edges of said rails being slightly immersed below the normal level of liquid in the tank, and means for rolling a upon said rails from one side of the tank to the other and for then elevating the pipe over the side of the tank, said means comprising a crank shaft rotatably journalled in a position adjacent and parallel to the normal surface of the liquid and to the side of the tank toward which the pipe is rolled, and at least two nger like cams each having an end rotatably journalled at spaced points on said shaft with their free ends extending across the tank and rotatable in vertical planes, the upper pipe rolling edge of the free end of each cam having a concave curvature and a length at least equal to the circumference of the pipe while the journalled pipe elevating end of each cam has an upper convexly curved edge of shorter length.

2. Apparatus as described in claim I in which each pipe rolling cam in its normally inoperative position is held by gravity with most of its length y immersed below liquid in the tank, and in which the curvature of the convex upper edge of the the curvature of the concave pipe rolling edge and intersects the concave edge to for an angle greater than 9().

3. An apparatus for coating a cylindrical cb.- ject including a tank for coating liquid, means in said tank providing a support for the object and maintaining the same parallel with the surface of the liquid in the tank and slightly immersed therein, and cam means mounted to contact the outer surface of said object and roll the same upon said supporting means.

4. An apparatus for coating cylindrical objects including a tank for coating liquid. means in said tank providing a support for the object and maintaining the same parallel with the surface of the liquid in the tank and slightly immersed therein, and cam means mounted to contact said object at a point adjacent the submerged portion thereof and roll the same across said tank.

5. An apparatus for coating cylindrical objects including a tank for coating liquid, means for supporting the object parallel to the surface-of the liquid in the tank and slightly immersed therein, and cam means having a portion submerged in said liquid and mounted to contact said object upon the submerged portion thereof to roll the same across the tank.

6. An apparatus for coating cylindrical objects including a tank for coating liquid, means for supporting said object parallel to the surface of including a tank for coating liquid, means for` supporting the object parallel to the surface of the liquid in the tank and slightly immersed length of pipetherein, cam means having an element shaped and positioned to contact the object and `roll the same across the tank, and a second cam elesupporting the object parallel to the .surfaceof the liquid in the .tank and slightly immersed length thereof to roll the same across the tank for a. distance at least equal to the circumference of the object. l

KARL H. FULTON. 

